The present invention relates to a sliding rail assembly for drawer and more specifically, to an auto locking structure used in a sliding rail assembly for drawer, which is easy to assembly with less labor and time consumption and, which achieves locking action positively.
FIGS. 1 and 2 illustrate a sliding rail assembly auto locking structure used in a sliding rail assembly 8 for drawer. This sliding rail assembly auto locking structure comprises a holder base 81, a link 82, and a movable block 83. This design of sliding rail assembly auto locking structure is complicated, resulting in high manufacturing cost and high installation difficulty. Further, the movable block 83 may be biased accidentally during installation or use, thereby causing the locating block 841 of the inner sliding rail 84 unable to push the movable block 83. In this case, the inner sliding rail 84 cannot be returned to the received position.
FIG. 3 shows another design of sliding rail assembly auto locking structure used in a sliding rail assembly 9 for drawer. According to this design, the sliding rail assembly auto locking structure comprises a holder base 91, a spring member 92, a link 93, and a push block 941 at the inner sliding rail 94. This design of sliding rail assembly auto locking structure is still not satisfactory in function. Because the spring member 92 has the two ends thereof turned at right angles after installation, the spring member 92 wears quickly with use and tends to deform permanently. Further, because the spring member 92 is exposed to the outside of the sliding rail assembly, it may be forced out of the sliding rail assembly accidentally.
Therefore, it is desirable to provide a sliding rail assembly auto locking structure that eliminates the aforesaid drawbacks.
The present invention has been accomplished under the circumstances in view. It is therefore the main object of the present invention to provide a sliding rail assembly auto locking structure, which is inexpensive to manufacture and easy to install. According to one aspect of the present invention, thee sliding rail assembly auto locking structure is comprised of a locating block, a movable hook, a spring member, and a holder base. The simple structure design is inexpensive to manufacture and easy to install. According to another aspect of the present invention, the movable hook has frond and rear guide rods by which the movable hook can be moved forwards/backwards along two parallel longitudinal sliding slots in a longitudinal sliding track of the holder base smoothly. When pulling the drawer from the received position to the extended position, the front guide rod of the movable hook will be forced into locating holes of the holder base to disengage the movable hook from a locating block at the inner sliding rail, for enabling the inner sliding rail to be moved with the drawer to the extended position. When pushing the drawer backwards from the extended position to the received position, the locating rod of the locating block at the inner sliding rail will be moved over a sloping front guide face into a locating groove at the movable hook and forced against the back wall of the locating groove to bias the movable hook, enabling the spring member to pull the movable hook backwards to the rear end of the longitudinal sliding slots. According to still another aspect of the present invention, the holder base comprises a protruding wall projecting into the rear part of the bottom open side of the longitudinal sliding track to shield the spring member, keeping the spring member in place. According to still another aspect of the present invention, the holder base comprises two guide grooves bilaterally formed in the longitudinal siding track and respectively extended from the front end of the longitudinal sliding slots to the topmost edge of the longitudinal sliding track for easy insertion of the guide rods of the movable hook into the longitudinal sliding slots of the longitudinal siding track during installation. According to still another aspect of the present invention, the spring member is linearly stretchable for durable use.